Tandem axle trailers characteristically exhibit several functional advantages over single axle trailers. For example, tandem axle trailers double the number of load bearing points upon the under surface of a trailer's chassis or frame, enabling the frame to effectively carry a greater load. Also, tandem axle trailers are more stable and have less tendency to sway while being pulled along a highway at high speeds. Also, in the event of a trailer tire blowout, tandem axle trailers are less likely than single axle trailers to experience a catastrophic failure and crash.
Where a tandem axle trailer is to be parked upon a sloped surface, such trailers offer further advantages over single axle trailers. In order to secure a single axle trailer against down slope rolling, tire chocks are commonly wedged between such trailer's tires and the ground or pavement. Such chocks are necessarily placed at the down hill or down slope side of the tires. When such trailer's tires roll or bias in the down slope direction against such wheel chocks, a combination of forces is directed against the wheel chocks, simultaneously driving the wheel chocks downwardly into the ground or pavement, and rearwardly away from the tires. Such rearwardly directed force may, on occasion, undesirably cause the tire chocks to eject rearwardly from beneath the tires, especially during low friction wet or icy weather conditions. Provision of mechanical structures which resist such chock ejection is desirable. However, single axle trailers typically present no structural surface which is suitable for countering such rearwardly directed force component. In contrast, tandem axle trailers do present a convenient structure (i.e., a rearwardly oriented second tire) as a source of base support for opposing such rearward chock ejecting force. Apparatus including paired wheel chocks and paired tire biasing friction plates which are adapted for alternate extension and retraction between longitudinally paired tires of a tandem axle trailer are known. Such apparatus may be categorized generally into two classes.
In a first class of such tandem axle tire securing apparatus, front and rear tire chocks beneficially dually engage both the ground and an up slope tandem axle trailer tire. Such tire engagement allows the down slope rolling bias of the uphill tire to frictionally lock the up hill chock between the ground and the tire. However, chock spreading mechanisms which are typically associated with such paired tire chocks are commonly positioned at or near ground level, requiring an operator to undesirably stoop to an elevation at or near ground level in order to manipulate such apparatus's actuating controls.
In a second class of the apparatus identified above, front and rear tire biasing friction plates engage longitudinally paired tires of a tandem axle trailer by biasing between such tires without any ground contact. Such apparatus advantageously minimize stooping needed for installation and de-installation of the device. However, the mechanical function of such apparatus undesirably relies exclusively upon force applied by its friction plate spreading mechanism to lock the longitudinally paired tires against rolling. In use of such mechanisms, the down hill or down slope rolling bias of the tires is incapable of wedging the mechanism against the ground for an additional tire locking effect. Instead, such apparatus undesirably tends to urge the mechanism to a tire releasing position. Any failure of the friction plate spreading mechanism or any rollable sliding along the friction plates may result in a release of tires and a catastrophic accident.
The instant inventive trailer tire chocking apparatus solves or ameliorates the problems discussed above by providing apparatus and structure which facilitates the above described protective utilization of ground wedging wheel chocks and by ergonomically facilitating installation, actuation and alternate removal of the apparatus without undue bending or stooping.